Keyboard triggered percussion sound producing device for keyboard electronic musical instrument

ABSTRACT

In an electronic organ including tone generators, key switches associated with playing keys in the keyboard for respectively switching signals from the tone generators, and a mixing circuit for mixing the switched signals; a percussion sound producing device comprises a depressed-key number detecting circuitry for generating a D.C. voltage responsive to the number of simultaneously depressed keys in the keyboard, a trigger signal generating circuitry fed with the D.C. voltage and generating a trigger signal when the D.C. voltage exceeds a predetermined value, and a percussion sound signal generator for generating percussion sound signals triggered by the trigger signal. In an electronic organ, for example, when two or more keys in the keyboard are depressed concurrently, there is produced maracas sound in addition to the musical-scale sounds; but when only one key is depressed at a time, there is produced only a musicalscale sound but no maracas sound.

United States Patent 1191 Adachi et al.

l 1March 13, 1973 1 KEYBOARD TRIGGERED PERCUSSION 3,333,041 7/1967 Munch et al 84/126 x SOUND PRODUCING DEVICE FOR 2,433,234: 1992;; grand; "322g:

,4 4, l c mi t. fi S, E E MUSICAL 3,493,668. 2/1970 Bunger ..84/l.l3 [75] Inventors: Takeshi Adachi; Syoichi Suzuki, Primary Examiner-Richard B. Wilkinson both of Hammamatsu, Japan Assistant Examiner-Stanley J. Witkowski [73] Assignee: Nippon Gakki Seizo Kabushiki A'tomey ostmlenk Faber Gerb & Soffen Kalsha, Hammamatsu-sh1, Japan [57] ABSTRACT [22] Filed: Aug. 9, 1971 In an electronic organ 1nclud1ng tone generators, key [21] Appl. No.: 170,359 switches associated with playing keys in the keyboard for respectively switching signals from the tone 1, Related Apphcatlon Data generators, and a mixing circuit for mixing the [63] Continuation of 3 No, 359 73 Sept 22 19 9 switched signals; a percussion sound producing device abandoned. comprises a depressed-key number detecting circuitry for generating a DC. voltage responsive to the Forelgn pp Prlorlty Data number of simultaneously depressed keys in the keyboard, a trigger signal generating circuitry fed with 'g z i? japan the DC voltage and generating a trigger signal when apan the DC. voltage exceeds a predetermined value, and a 52 Us. (:1 .;.....s4/1.13 84/126 Percussim Smmd Signal genera gene'aing [51] Int. Cl. ..-....G l0h 1/00 cussion sound signals triggered by the trigger signal In [58] Field of Search ..s4/1.01, 1.13, 1.17, 1.24, F example when mm 84/126 DIG l2 DIG 23 keys 1n the keyboard are depressed concurrently, there is roduced maracas sound in addition to the P [56] Referencescited musical-scale sounds; but when only one key is depressed at a time, there is produced only a musical- UNITED STATES PATENTS scale sound but no maracas sound. 3,309,453 3/1967 Park ..84/l .l3 7 Claims 5 Drawing Figures 3,321,567 5/1967 Munch et al. ..84/l.l3

KEY PERC SW ADD PULSE DISCR TRIG GEN PATENTEUHAR 1 31975 SHEET 1 BF 2 FIG.1

PERC GEN TRIG DISCR PULSE ADD KEY SW FIG.2

F I G. 3

KEY SW PERC GEN SCHMITT ADD PATENTEUHARIIHSB 76 SHEET 2 BF 2 TONE KEY GEN sw M X y FILT PERC SCHMIT RECT T GEN PERC 5/ 2 DISCR TRIG GEN A 1 VOLT GE N 23 2 5 27 29 PERC DISCR TRIG GEN fi .22, 1969, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to an electronic musical instrument, and more particularly to an electronic organ hav- 1 ing percussion accompaniment effects triggered by the normal playing keys in the musical scale keyboard.

There are known in the prior art electronic musical instruments which can produce percussion sounds by means of an interlocking keying device, wherein percussion sounds are triggered by the operation of keys in the musical-scale keyboard. These electronic musical instruments have had several defects, and one of the defects in a type to produce percussion sound according to every key depression is that the accompanying percussion sounds are generated whenever and in whatever way the key is depressed irrespective of the kind of the play on the musical-scale keyboard, although the accompanying percussion sounds are undesirable in the case of playing broken chords (Alberti bass) or counter-melodies while the accompanying percussion sounds are desirable in the case of playing unbroken chords to beat the rhythm pattern. Therefore, it requires extra manipulations of stop tablets or tone levers in accordance with the kind of the play on the keyboard to meet the above-mentioned desirabilities. Another defect of this type is that the percussion effect is not desirable in certain instances owing to the poor variation of rhythms of the percussion, because the percussion sounds produced interlocking to the keyboard proceeds in a same tone-color throughout.

There has been another type of an electronic musical instrument which produces different percussion sounds in accordance with the difference of the played keyboards, one according to the interlocking keying in response to the lower keyboard and the other to the pedal keyboard, however, it requires intensive practice necessitating the use of both hands and feet, and it is unsuited for the average player. Examples of this technique are set forth in U. S. Pat. Nos. 3,317,649 and 3,340,344.

SUMMARY OF THE INVENTION A principal object of the present invention is to eliminate the above mentioned defects appearing in prior art electronic musical instruments.

In accordance with the present invention, an interlocking keying device for percussion causes a tonecolor to be different corresponding to the case whether produced by means of simultaneously depressing a plurality of keys in the same keyboard, or produced by means of pushing any one of said keys separately, whereas it may produce no percussive sound when said one key is pushed separately. In accomplishing the above mentioned object, the interlocking keying device for percussion according to the present invention comprises an output circuit which supplies power in response to the number of depressed keys in the same keyboard at a time, and a discriminator circuit which discriminates the supplied powers from the output circuit to transmit the signals to the tone generator to produce percussion sounds.

In this specification, the word keyboard means a normal keyboard of an electronic organ for playing musical-scale sounds such as upper keyboard, lower keyboard and pedal for the keyboard, and the word key is defined as each playing key in the respective keyboards.

BRIEFDESCRIPTION OF THE DRAWINGS The'invention will be better understood from the following description taken in connection with the accompanying drawings in which:

FIG. l is a block diagram illustrating the first embodiment of the invention;

FIG. 2 is a circuit diagram illustrating said embodiment;

FIG. 3 is a block diagram illustrating the second embodiment of the invention;

FIG. 4 is a block diagram illustrating the third embodiment of the invention; and

FIG. 5 is a block diagram illustrating the fourth embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Example I This embodiment relates to an interlocking keying device for percussion which produces percussion sounds only in the case of playing a plurality of sounds (chords etc.) whereas it produces no percussion soundin the case of playing melody with a single sound on the same keyboard.

The inventors of the invention were interested in the fact that two or more keys in a musical instrument were pushed at a time in playing rhythm with chords, while generally only one key in a musical instrument was pushed in playing melodies, broken chords or countermelodies. Thereby, they intended to provide an interlocking keying device for percussion, wherein a percussion sound is produced only in the former case, that is, a percussion sound is produced when two or more keys are depressed at a time, whereas no percussion sound is produced when only one key is depressed.

The following will illustrate the embodiment taken in connection with the accompanying drawings. FIG. 1 is a block diagrammatic representation of the embodiment, wherein I is a group of switches, provided separately in addition to the normal musical-scale signal keying switches, interlocked with keys of a keyboard to trigger percussion sounds. 2 is an adding circuit, 3 is a pulse generating circuit by which the supplied power from the adding circuit 2 is converted into a pulse, 4 is a pulse amplitude discriminator circuit by which supplied pulses are discriminated by their pulse amplitude and only the pulses having amplitudes over a predetermined value are allowed to pass through, 5 is a trigger generating circuit, and 6 is a percussion signal generator.

The keys I and the adding circuit 2 constitute a depressed-key number detecting circuitry which generates a D.C. voltage responsive to the number of concurrently depressed keys in the keyboard; the pulse generating circuit 3 the discriminator circuit 4 and the trigger generating circuit 5 constitute a trigger signal generating circuitry which is fed with the D.C. voltage and generates a trigger signal if the DC. voltage exceeds a predetermined value; and the percussion signal generator 6 generates percussion (e.g. maracas) sound signals when triggered by the trigger signal.

Referring now to the detailed circuit diagram of FIG. 2 wherein like reference numerals indicate like parts in FIG. 1, the function of the device will be explained as follows.

When a certain key is depressed to play a musicalscale tone, the switch S, associated with the same key is also closed, and in turn a D.C. voltage is developed at point (a) according to the resistance ratio of the resistor R associated with switch S and resistor R Due to this DC voltage, charging current flows into capacitor C and a pulse voltage is generated across resistor R The pulse width of this pulse voltage is about 50-100 milli-seconds and its pulse amplitude increases corresponding to the number of pushed keys. Diode D is provided to quicken the return and to absorb the opposite polarity pulse induced at the time of opening of the switch. Said pulse voltage is then applied to the pulse amplitude discriminator circuit 4 which consists of resistors R and R (these may be adjustable resisters, and in this case, it can be used similarly as a type heretofore in use to produce percussion sound according to one key-pushing), and diode D This pulse amplitude discriminator circuit functions to discriminate the'amplitude of said pulse voltage, wherein it is constituted so as to flow current through diode D and resistor R and to raise the electric potential at point (b) only in the case when the pulse amplitude is over a predetermined value (set by the values of R and R Accordingly, when only one key is pushed and the associated switch S is closed, to the exclusion of the remaining switches, no trigger pulse is generated from trigger generating circuit 5 and correspondingly no percussion signal is produced from percussion signal generator 6.

However, when two keys are pushed and the corresponding switches, for instance, switches S, and S are closed, DC voltage at point (a) reaches a value which is calculated from the ratio, R /2 to R and accordingly the amplitude of a pulse from pulse circuit 3 becomes greater compared to the above case and the electric potential at point (b) in pulse amplitude discriminator circuit 4 is raised, and a trigger pulse is generated at the output side of trigger generating circuit 5. That is, in this case, trigger generating circuit 5 is constituted so as to be operated with a voltage level at point (b) only when said voltage is generated according to that two or more switches are closed in response to the pushing of the interlocking keys. Consequently, the trigger pulse from trigger generating circuit 5 operates percussion signal generator 6 to produce percussion sounds.

Further, it is able to discriminate not only single sound from a plurality of sounds but also, two or less sounds from three or more sounds, and still further, three or less sounds from four or more sounds, if the operating level of the trigger generating circuit is adjusted suitably.

Example 2 FIG. 3 is a block diagram of this embodiment, wherein a Schmitt circuit 7, constituting the trigger signal generating circuitry in place of the circuits 3, 4 and 5 of FIG. 1, is connected between the adding circuit 2 and the percussion signal generator 6. When switches, which are interlocked to keys corresponding to three notes in the key-board are closed, the output power of the adding circuit 2 achieves or surpasses a certain level. If the Schmitt circuit is set to operate at this level, then, the Schmitt circuit 7 operates according to the pushing of three keys, for example, and supplies a trigger pulse to percussion signal generator 6 to produce percussion sounds. Of course, a percussion sound is produced when three keys are pushed almost at a same time, and also a percussion sound can be produced when the three keys are in a pushed state by pushing keys one by one additively.

Example 3 FIG. 4 is a block diagram of this embodiment comprising: a conventional system employed in an electronic musical instrument which consists of tone generators 8, keying switches 9, mixing circuit 10 and filters 11; and in addition thereto a rectifier circuit 12 whereby musical-scale tone signals from mixing circuit 10 are rectified; and a Schmitt circuit 13 which is operated by DC voltage over a predetermined value supplied from said rectifier circuit; and the percussion signal generator 6 which produces percussion sounds according to the trigger pulse from the Schmitt circuit 13. The system to produce percussion sounds in this embodiment is almost the same as that in embodiment 2 as shown in FIG. 3, wherein, if the operation level of the Schmitt circuit 13 is set at a certain level less than the level of the voltage generated at the output side of the rectifier circuit 12 when two keying switches are closed, then the Schmitt circuit 13 works when two or more keying switches are closed and percussion signals are produced from percussion signal generator. Accordingly, it need not to be equipped with extra interlocking keying switches for percussion in this embodiment.

As above described, embodiments l, 2 and 3 are all constituted so as to be able to produce percussion sounds according to the number of the keys depressed without any extra manipulation of the tablets etc. and are very effective practically.

Example 4 When playing in concert with ordinary musical instruments, for instance, in playing waltz, generally, rhythm is played on several percussion instruments, such that, the first beat is played on cymbals, the second and the third beats are played on maracas.

This embodiment is an interlocking keying device for percussion equipped in an electronic musical instrument which enables the playing to be nearly that of natural musical instruments, wherein tone-colors of percussions are made to be different in respect to the number of pushed keys in the same keyboard, for instance, the first tone-color of percussion is produced when one key is pushed, while the second tone-color of percussion is produced when a plurality of keys in the same keyboard are pushed at a same time.

In detail, the embodiment will be described in connection with FIG. 5 as follows:

Numeral 21 is a circuit which generates an output voltage in response to the number of pushed keys, 22 and 23 are discriminator circuits which discriminate the supplied voltage from the circuit 21 wherein 22 detects voltage less than a certain value, while 23 detects voltage over a certain value 24 and 25 are trigger generating circuits, wherein the circuit 23 generates trigger signals only when said output voltage is detected in discriminator circuit 22 to be less than the predetermined value, while the circuit 25 generates trigger signals only when the output voltage detected in discriminator circuit 23 is above the predetermined value. 26 and 27 are percussion signal generators which produce percussion signals of different tone-colors cor- .responding to trigger signals from trigger generating circuits 24 and 25 respectively. These percussion signals are applied to system of normal musical signals in line 30 through volume regulators 28 and 29 respectively, and amplified by an amplifier 31 and radiated as acoustic sounds by a loudspeaker 32.

Here, discriminator circuits 22 and 23 are constituted so as to be actuated at a predetermined level using Schmitt circuits or AND circuits, for instance. And two percussion signal generators 26 and 27 may consist of oscillators which generate percussion signals of different tone-colors being controlled directly by respective trigger signals from said trigger generating circuits 24 and 25, or they may be constituted to be one percussion signal oscillator of continuous oscillation, wherein the output signals is led to two switch circuits to be controlled by said respective trigger signals to produce different tone-colors through tone forming circuits, such as filters respectively connected to the output side of the switch circuits. Further, volume regulators 28 and 29 may, of course, be either variable resistors capable of varying the magnitude of signals continuously, or switches to switch on and off the signals.

Now, the setting level of the discriminator circuit 22 is made to set at the output voltage of the circuit 21 in the case where only one key is pushed, and the setting level of the discriminator-circuit 23 is made to set at the output voltage of the circuit 21 in the casewhere two keys are pushed, and the tone-color of the percussion signal generator 26 is made to be of cymbals and the tone-color of the percussion signal generator 27 is made to be of maracas. Then, when one key is pushed, the trigger generating circuit 24 operates the percussion signal generator 26 according to the detection of the discriminator circuit 22, and produces cymbal tone signals. And next, when two keys are pushed, the trigger generating circuit 25 operates the percussion signal generator 27 according to the detection of the discriminator circuit 23 and produces maracas tone signals. Here, the discriminator circuit 22 is easily constituted with an AND circuit which receives a negation of the discriminator circuit 23 and an affirmation (output existence) of the circuit 211.

'And further, it is able to detect the difference between a single sound and a plurality of sounds, also between two or less sounds and three or more sounds, and further between three or less sounds and four or more sounds by means of the adjustment of the setting level of each discriminator circuits 22 and 23.

As described above, according to this embodiment, it is possible to produce percussion sounds of different tone-colors in response to the number of depressed keys, as the tone-color produced when only one key in a keyboard is pushed has a different tone-color from that produced when a plurality of keys in the same keyboard are pushed at a same time, consequently it is very easy to play a musical selection with a full variety of rhythms using only one keyboard, and which has a further capability of generating musical sounds which very closely resemble those sounds generated by conventional musical instruments.

Moreover, by means of the regulation of volume regulators 28 and 29, it isalso possible to produce percussion sounds in every pushing as those in use in present day. Further, it is possible to produce no percussion sound in the case of playing broken chord or counter melody, while it is possible to produce percussion sound only in the case of playing chords by pushing a plurality of keys in the same keyboard at a same time, and thus it is practically very useful.

What is claimed is:

1. An interlocking keying device for an electronic musical instrument having tone generators and a keyboard comprising a plurality of playing keys for playing musical-scale tones, said device comprising:

a summing circuit having plural inputs;

a DC. source;

key switches each operated by an associated playing key for coupling said D.C. source to one of said plural inputs upon depression of an associate playing key;

a discriminator circuit coupled to the output of said, adding circuit and comprising a pulse generating circuit by which an output supplied from said adding circuit is converted into a pulse, and a pulse amplitude dis-criminator circuit coupled to the output of said pulse generating circuit and responsive to the pulse amplitude of each pulse received from said pulse generating circuit to pass pulses which have over a predetermined amplitude; a trigger generating circuit coupled to said discriminator for generating a trigger signal respon-v sive to a pulse developed by said discriminator,

and a percussion generator coupled to said trigger generating circuit for generating a percussion signal responsive to said trigger signal.

' 2. An interlocking keying device for percussion according to claim ll; wherein the pulse generating circuit, pulse amplitude discriminator circuit and trigger generating circuit of said discriminator circuit collectively comprise a Schmitt circuit.

3. In an electronic musical instrument having a keyboard including a plurality of playing keys each key having a switch for generating a signal when its key is depressed; a keyboard trigger percussion sound producing device comprising a depressed-key number detecting circuit having means for summing the outputs of the key switches to generate a DC. voltage responsive to the number of concurrently depressed keys in said keyboard, a trigger signal generating circuitry coupled to said detecting circuitry and fed with said DC. voltage for generating a trigger signal when said DC. voltage exceeds a predetermined value, and a percussion sound signal generator coupled Y to said trigger signal generating circuit for generating percussion sound signals when triggered by said trigger signal.

4. A keyboard trigger percussion sound producing device according to claim 3, wherein said depressedkey number detecting circuitry includes a D.C. power source; said key switches being associated with said keys and each having a switch terminal for coupling said D.C. power source to an input terminal associated with a depressed key and said summing means comprising an adding circuit coupled to said input terminal which adds the switched D.C. inputs applied to said adding circuit.

5. A keyboard trigger percussion sound producing device according to claim 3, wherein said trigger signal generating circuitry includes a pulse generating circuit which converts the D.C. voltage from said depressedkey number detecting circuitry into a pulse having an amplitude proportional to said D.C. voltage, a pulse amplitude discriminator circuit coupled to said pulse generating circuit for passing only those pulses having an amplitude over a predetermined value, and a circuit coupled to said pulse amplitude discriminator circuit for producing a trigger pulse when supplied with a pulse through said discriminator circuit.

6. A keyboard trigger percussion sound producing device according to claim 3, which further comprises a second trigger signal generating circuitry coupled to and fed with the D.C. voltage from said depressed-key number detecting circuitry and generating a second trigger signal when said D.C. voltage is below a predetermined value, and a second percussion sound signal generator coupled to said second trigger signal generating circuitry for generating a second percussion sound signal different from that of the first mentioned percussion sound signal generator when triggered by said trigger signal.

7. In an electronic musical instrument having a keyboard including a plurality of playing keys for playing musical-scale tones, tone generators for providing musical-scale tone signals, key switches each associated with each of said keys for keying each of said tone signals, and a mixing circuit coupled to said key switches for receiving signals keyed by said key switches and producing a mixed output signal; the keyboard trigger percussion sound producing device being comprised of a rectifier circuit fed with said mixed output signal for producing a D.C. period voltage proportional to an amplitude of said mixed output signal; a trigger signal generating circuit fed with said D.C. voltage for generating a trigger signal when said D.C. voltage exceeds a predetermined value; and a percussion sound signal generator for generating percussion sound signals when triggered by said trigger signal. 

1. An interlocking keying device for an electronic musical instrument having tone generators and a keyboard comprising a plurality of playing keys for playing musical-scale tones, said device comprising: a summing circuit having plural inputs; a D.C. source; key switches each operated by an associated playing key for coupling said D.C. source to one of said plural inputs upon depression of an associate playing key; a discriminator circuit coupled to the output of said adding circuit and comprising a pulse generating circuit by which an output supplied from said adding circuit is converted into a pulse, and a pulse amplitude dis-criminator circuit coupled to the output of said pulse generating circuit and responsive to the pulse amplitude of each pulse received from said pulse generating circuit to pass pulses which have over a predetermined amplitude; a trigger generating circuit coupled to said discriminator for generating a trigger signal responsive to a pulse developed by said discriminator; and a percussion generator coupled to said trigger generating cIrcuit for generating a percussion signal responsive to said trigger signal.
 1. An interlocking keying device for an electronic musical instrument having tone generators and a keyboard comprising a plurality of playing keys for playing musical-scale tones, said device comprising: a summing circuit having plural inputs; a D.C. source; key switches each operated by an associated playing key for coupling said D.C. source to one of said plural inputs upon depression of an associate playing key; a discriminator circuit coupled to the output of said adding circuit and comprising a pulse generating circuit by which an output supplied from said adding circuit is converted into a pulse, and a pulse amplitude dis-criminator circuit coupled to the output of said pulse generating circuit and responsive to the pulse amplitude of each pulse received from said pulse generating circuit to pass pulses which have over a predetermined amplitude; a trigger generating circuit coupled to said discriminator for generating a trigger signal responsive to a pulse developed by said discriminator; and a percussion generator coupled to said trigger generating cIrcuit for generating a percussion signal responsive to said trigger signal.
 2. An interlocking keying device for percussion according to claim 1; wherein the pulse generating circuit, pulse amplitude discriminator circuit and trigger generating circuit of said discriminator circuit collectively comprise a Schmitt circuit.
 3. In an electronic musical instrument having a keyboard including a plurality of playing keys each key having a switch for generating a signal when its key is depressed; a keyboard trigger percussion sound producing device comprising a depressed-key number detecting circuit having means for summing the outputs of the key switches to generate a D.C. voltage responsive to the number of concurrently depressed keys in said keyboard, a trigger signal generating circuitry coupled to said detecting circuitry and fed with said D.C. voltage for generating a trigger signal when said D.C. voltage exceeds a predetermined value, and a percussion sound signal generator coupled to said trigger signal generating circuit for generating percussion sound signals when triggered by said trigger signal.
 4. A keyboard trigger percussion sound producing device according to claim 3, wherein said depressed-key number detecting circuitry includes a D.C. power source; said key switches being associated with said keys and each having a switch terminal for coupling said D.C. power source to an input terminal associated with a depressed key and said summing means comprising an adding circuit coupled to said input terminal which adds the switched D.C. inputs applied to said adding circuit.
 5. A keyboard trigger percussion sound producing device according to claim 3, wherein said trigger signal generating circuitry includes a pulse generating circuit which converts the D.C. voltage from said depressed-key number detecting circuitry into a pulse having an amplitude proportional to said D.C. voltage, a pulse amplitude discriminator circuit coupled to said pulse generating circuit for passing only those pulses having an amplitude over a predetermined value, and a circuit coupled to said pulse amplitude discriminator circuit for producing a trigger pulse when supplied with a pulse through said discriminator circuit.
 6. A keyboard trigger percussion sound producing device according to claim 3, which further comprises a second trigger signal generating circuitry coupled to and fed with the D.C. voltage from said depressed-key number detecting circuitry and generating a second trigger signal when said D.C. voltage is below a predetermined value, and a second percussion sound signal generator coupled to said second trigger signal generating circuitry for generating a second percussion sound signal different from that of the first mentioned percussion sound signal generator when triggered by said trigger signal. 